1. FIELD OF THE INVENTION
This invention relates to a floor treating machine for cleaning or polishing floor surfaces, and more particularly to a floor treating machine having a floor treating device such as a brush or sponge attached for unitary rotation to a lower end of a vertical rotary shaft driven by an electric motor, the floor treating device supporting the entire machine during a floor treating operation.
2. DESCRIPTION OF THE RELATED ART
Conventionally, this type of floor treating machine has four wheels which constantly engage a floor surface since the machine carries a heavy battery running a risk of damaging a carpet or other floor material with liquid leakage. The machine cleans the floor by rotating the brush with the four wheels constantly engaging the floor, i.e. with the four wheels bearing a large part or the whole of the machine's weight.
DC type floor treating machines having the wheels in constant engagement with the floor include a push type and a self-propelled type. These types invariably are movable with the four wheels engaging the floor, and are therefore not capable of making small sharp turns. Such machines are not suited for cleaning corners or narrow areas. Moreover, since the entire machine is large and heavy and with the possibility of leakage from the battery, it is difficult to transport the machine upstairs from the first floor to the second floor or from the second floor to the third floor, or downstairs from the second floor to the first floor or from the third floor to the second floor, and to store the machine when out of use.
To overcome such inconveniences, various types of floor treating machines have been proposed which are capable of small sharp turns and easy to transport upstairs and downstairs. These machines are used to clean floors with wheels maintained out of contact with the floors.
This type of machines, which have the wheels out of contact with the floors when in use, are all AC-operated and have a long power cord. Such machines are extremely cumbersome in use, with the long power cord constantly obstructing movement of the machine during a cleaning operation.